Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?
Space NASA

Saturn's F Ring Is Now Three Times As Wide As During the Voyager Flybys 41

KentuckyFC writes In 1980 and 1981, Voyager 1 and 2 flew past Saturn providing unprecedented images of its magnificent ring system. At that time, its most distant discrete ring, the F ring, was about 200 kilometres wide. But puzzlingly, images sent back by Cassini show that the ring is now 580 kilometres wide and twice as bright as it was thirty years ago. Now astronomers think they have finally solved the mystery of the expanding F ring. The ring is shepherded by a number of small moons, the most famous of which is Prometheus. These moons interact gravitationally with the ring creating structures such as braids and spokes. The new thinking is that the moons' orbits resonate with the F ring, pushing clouds of dust and ice further away from Saturn. This makes the ring wider. But beyond a certain radius the orbit of the dust becomes unstable and it begins to spiral back towards Saturn and collides with the rest of the ring. This causes a chain reaction of collisions that dramatically increases the number of particles in the ring and hence its brightness. This theory also leads to a prediction--the resonant process is currently at a maximum but should reduce sharply in the coming years, if the theory is correct. So by 2018, the F ring should be back to the same configuration the Voyagers saw in 80/81.
This discussion has been archived. No new comments can be posted.

Saturn's F Ring Is Now Three Times As Wide As During the Voyager Flybys

Comments Filter:
  • 3rd grade cussin'. "but, Mom, it's science!"
  • by Runaway1956 ( 1322357 ) on Monday September 01, 2014 @09:34AM (#47799717) Homepage Journal

    This increase in the size of the F ring is almost certainly caused by man made global warming. If we don't stop doing everything that we do, the whole solar system is likely to come tumbling down on our heads!

  • The Fithp are coming

  • by Anonymous Coward on Monday September 01, 2014 @10:22AM (#47799899)

    As I write this, there are 12 comments to this story. They are all total crap.

    Five are about enlarged bodily orifices, namely the anus and the vagina. One of them even features references to prison rape.

    Three are about global warming and human-induced environment changes.

    One is about religion.

    Two of them just drop stupid sci-fi references.

    The remaining one is really weird stupidity about 3rd grade swearing or something idiotic like that.

    All of them have absolutely nothing useful to say, and most of them aren't even tangentially related to the submission and its topic.

    Come on, this is unbelievable. While I've never expected particularly high standards for Slashdot and the discussion here, I think that this is a new low. In the past, a story like this would generate at least some good discussion.

    I'm not an astronomer, so I don't have much to add, but I would at least like to read comments from people who may have some experience within this field. Instead, all I find here is stupidity and discussion about torn anal sphincters.

    At this point, I don't know what to do. I can't stand reddit any longer, because the discussion there is even more inane than it is here. I'm tiring of Hacker News, because the only submissions there that get to the front page involve sexism or some other irrelevant social issue, rather than stuff relating to science, technology, and even business. Lobsters is totalitarian groupthink enforced by their invitation-only signup policy. SoylentNews isn't bad, but there isn't much discussion.

    Where can somebody go to find tolerable discussion about science, math, and technology?

    • Entirely disagree:

      While I've never expected particularly high standards for Slashdot and the discussion here,

      Entirely agree:

      I think that this is a new low.

      When I became a member ten years or so ago, and was a lurker for a few years before that, the jokes were always there, but mixed into an often in-depth discussion of math, science, programming, etc. I don't read or post as often as I used to (I was never a major contributor, and the few 5s I've ever gotten were for funny comments rather than for anything important) myself. Perhaps older users are simply moving on (only two of the comments are 6-digit UIDs, the others are

    • by MRe_nl ( 306212 ) []
      On a more serious note, although I agree with the sentiment of your comment, the first twelve monkeys to hit the typewriter won't always be the best informed. Sometimes it can take hours before someone with practical knowledge of the subject at hand chimes in. Added to that that moderation may take some time too there's always going to be crud before pearls. You can find more information on specialist websites, but there is often no discussion due the low visitor numbers on those sites or

    • The fact that you recognised both sci-fi references is also of note.

      I find that the more we learn about Saturn's rings (and is thus applicable to all planets with rings and shepherd moons) the greater the fascination that such structures aren't just a bunch of small rocks orbiting a planet but have behaviour that is of interest to chaos and complexity mathematicians that can only lead to greater understanding of the dynamics of such systems.

      (Is this the kind of comment you were hoping for?)

    • IS labor day. Point being that those who aren't out just to troll, and more likely to bring substance to the discussions are probably out enjoying their holiday.

    • Well, some comments are funny and welcome. The problem lies in the fact that now is so easy to use a computer that the the football captains and the cheerleaders are appearing on Slashdot to comment (why, I really do not know), but without the necessary capacity and cultural baggage to comment something useful or interesting.

      But that said, it is important that you (and I, others, etc.) be tolerant, because though some are obviously stupid comments (like those involving bodily functions) others may not be
    • Jame's Clerk Maxwell (yes, the same one with the equations) figured out that the ring's of saturn must be made up of small particles. He came to this conclusion because a solid ring would have an unstable orbit and any disturbance would cause it to crash into Saturn. A fluid ring would form blobs and waves. Since neither of these happened, Maxwell concluded that the rings must be made up of small particles in orbit around Saturn. Bonus, he figured this out in 1856! []

      Sort of am

    • If you want to discuss astronomy, go to It's got more of a practical, amateur-astronomy, bent to it, but some of the guys there are very knowledgeable. You have to seek them out in the appropriate sub-forum, though.
  • This is a really interesting finding. So far as I know, even a lowly 3 body gravitational interaction cannot be exactly predicted. I'm wondering though - if enough high quality observations of the F-ring can be gathered over a period of years, is it possible to use them as a life-sized demonstration of the N-body gravitational solution? And could we curve-fit or otherwise reverse-engineer the paths of specific particles (or groups of them) to come up with (at least) better approximations for such N-body

The F-15 Eagle: If it's up, we'll shoot it down. If it's down, we'll blow it up. -- A McDonnel-Douglas ad from a few years ago